Sailing in the Indian Ocean is determined by the monsoon winds, which are caused by the difference in temperature between the massive Himalayan Plateau and the sea.
Monsoons are so predictable – and so important – that they were later incorporated into calendars, which illustrated the highly synchronised system of regular shipping between Egypt, East Africa, India and the Gulf. Ships sailing from Egypt for India would be carried by the southwest monsoon which ends in September. They could then trade in India until it was time for the northeast monsoon starting in December, which would carry them back home to Egypt and, via the Red Sea–Nile Canal, back to the Mediterranean. They had a free ride each way.
India had three main ports – Lothal, Cambay and Muziris – which were important in the Bronze Age, specialising in exports.
Gavin believes that there was a substantial exchange of goods and ideas. Minoan ships took copper and tin to India and returned with ivory and cotton and perhaps many Indian ideas about town planning, civic engineering and astronomy. Sooner or later, Indian shipowners would have wanted their vessels to accompany Minoan ships across the world, to collect valuable goods for themselves.
Further reading:
Monsoon patterns in the Indian Ocean: http://www.physicalgeography.net/fundamentals/7o.html
Professor A. Sreedhara Menon – A Survey of Kerala History:
http://en.wikipedia.org/wiki/A._Sreedhara_Menon
The Peutingerian Table, a set of maps dating from about AD 226 is said to show a temple of Augustus near Muziris: http://www.euratlas.net/cartogra/peutinger/
The accounts of Ibn Battuta describe his six visits to Calicut:
http://www.kerala.cc/keralahistory/index37.htm
http://www.kerala.com/kerala_historians/kerala_historian_Ibn%20Batuta.php
http://www.saudiaramcoworld.com/issue/196107/ibn.battuta.traveler.from.tangier.htm
Lothal:
http://asi.nic.in/asi_museums_lothal.asp
http://www.harappa.com/lothal
http://www.ahmedabadcity.com/tourism/html/lothal.html
Port of Cambay:
http://www.ancient-wisdom.co.uk/india.htm
Professor Cherian & colleagues, ‘Chronology of Pattanam: a multi-cultural port site on the Malabar coast’ : http://www.ias.ac.in/currsci/jul252009/236.pdf
Muziris, at last?: http://www.frontlineonnet.com/fl2708/stories/20100423270806200.htm